Compared with white noise jamming technology, correlation jamming technology is a more effective and feasible thousand jamming technology. The principle of correlation jamming technology is to use correlation jammer to send out correlation jamming signal that can automatically track the electromagnetic radiation signal of computer, so that the electromagnetic radiation signal is interfered, and the effect of random number encryption is achieved, so that the receiver can not demodulate the real information carried by the signal even if it receives the electromagnetic radiation signal. Because the correlation interference does not need to cover up the electromagnetic radiation signal to interfere, its transmission power does not need to be very strong, and the electromagnetic pollution to the environment is also very small. The correlation jammer is simple to use, compact in size, reasonable in price and remarkable in effect, which is most suitable for personal computers to work alone.
(2) Construction of electromagnetic shielding room. The principle of shielding technology is to use a metal mesh or metal plate with good conductivity to establish a six-sided shielding room or cage to surround the computer equipment that generates electromagnetic radiation and make it well grounded, thus inhibiting and blocking the propagation of electromagnetic waves in the air. A well-designed and installed shielding room has a good shielding effect on electromagnetic radiation. The shielding effect of high-performance shielding room can reach 140dB for electric field, 120dB for microwave field and 100dB for magnetic field. The problem that hinders the popularization and application of shielding technology is that the design, installation and construction requirements of shielding room are quite high and the cost is very expensive. Generally, the cost of a shielding room of 20 to 30 square meters needs hundreds of thousands to millions of yuan. Therefore, shielding technology is more suitable for computer equipment in some large data centers with high confidentiality requirements or occasions where several small computers are concentrated, such as national defense military data centers, large military command posts, data centers of intelligence agencies, etc.
(3) Configure low-radiation equipment. When designing and producing computer equipment, anti-radiation measures should be taken for components, integrated circuits, connecting wires and displays that may produce electromagnetic radiation, so as to minimize electromagnetic radiation. The production and use of low-radiation computer equipment is the fundamental protective measure to prevent the leakage of computer electromagnetic radiation.
Construction of shielding machine room
In order to effectively prevent the influence of electromagnetic interference noise and radiation on electronic equipment and measuring instruments, and prevent the leakage of electronic signals from threatening the security of confidential information, state organs, military, public security, banks, railways and other units need to establish shielded computer rooms.
In the design of the computer room, when the following requirements are met, the electromagnetic shielding design should be carried out in the design area:
(1) The computer room of the electronic information system of the data center involving state or enterprise secrets should be equipped with an electromagnetic shielding room, and the performance index of the electromagnetic shielding room should be implemented according to the relevant domestic standards.
(2) When the frequency is 0. 15~ 1000MHz, the radio interference field intensity in the main engine room is greater than 126dB, or the magnetic field interference environment field intensity in the main engine room is greater than 800A/m, so electromagnetic shielding measures should be taken in the design.
Shielding room can be divided into detachable and non-detachable: according to performance standards, it can be divided into national standard and military standard; The national military standard GJBz202 19~ 1994 is divided into class b and class c in terms of performance. According to the purpose of use, it is divided into confidential computer room to prevent information leakage and meta-electromagnetic environment computer room to prevent electromagnetic interference. Among them, the detachable type is mainly suitable for the shielding machine room that may be relocated. This kind of computer room is fast to install, can be disassembled and assembled many times, and is flexible and maneuverable; Non-detachable type is mainly suitable for large computer rooms, with good anti-leakage performance and high technical indicators, but the construction period is long.
Shielding machine room can make magnetic field extremely weak, and electric field, plane wave and microwave can be attenuated to the maximum extent. The shielding machine room is a fully enclosed hexahedron composed of metal plates, and is equipped with new shielding doors, ventilation systems, communication transmission systems, electrical lighting systems and other auxiliary facilities.